Tips for a bad credit car loan….please help!?

I got in an accident over Memorial Day weekend where I was stopped at a light and someone hit the car behind me, which hit me causing me to his the car in front of me. My insurance company went and did a estimate on the repairs and filed the car as a total loss. My car was pretty new a 2009 and I actually had bought it brand new at the end of 2008. However, now I’m in a situation where I need to buy a new car but the issue is that I have HORRIBLE credit. When I graduated from college I had numerous private loans through different lenders that merged with other companies or where completely bought out by other companies. I was never contacted to make payments and I tried to find all my loans and who they were through but I failed at that. So to make a long story short they only contacted me once they reported to a collection agency. Finally I got them all figured out through a Graduate Recovery program and have started making payments. But obviously the issue is that I have these delinquent marks on my credit. Additionally, I have some other credit issues that I just put into a debt management plan that I started paying this month.
So, I guess my question is I need to get a car loan, I have no way of getting to and from work without one. I don’t have strong cosigner, but I could probably put together $2,000 for some cash down. What else should I do? Or where else should I look? I’ve been declined for 0 down at 2 dealerships right now. I’m hoping to avoid an extremely high APR if at all possible. This is really frustrating because I’m trying so hard to get my credit together .
Thanks for the ideas, I live in CA I have looked for $2000 cars and haven’t found any that would work for me, I travel pretty far for work and I need a reliable car. I have already had 2 car loans that I went through that were NEVER delinquent and the second will be completely paid off within the month (insurance is paying for it).

I’m considering doing a cosign with my fiance, however I don’t want any of my past credit issues to effect his, so I’m hesitant to do this and mess with his good score.

I know I was really irresponsible with my credit and this is why I have really sat down and started to put all of my finances in order and I was actually really optimistic about establishing good credit for once and then this happens.
What would be the credit score of a cosigner that I would need to help me get a car loan?
Who is that number for? I’m working on my credit BUT I need a car to get work and one that is dependable! Ugghhhh